Keep the field indexes two record types agree on when taking their maximum

[g31pranjal]

A record type read off a descriptor carries the descriptor's field numbers, and those numbers may skip. Type.Record.defineProtoType() writes them back out as the field numbers of the descriptor it generates for the type, so two types that disagree about them generate descriptors that are not wire-compatible with each other.

Type.maximumType() rebuilt each field with Field.of(type, name), which has no index, so normalizeFields() renumbered every field by position. The maximum of two record types that agree on their numbering therefore lost that numbering — and MessageHelpers.deepCopyMessage(), which relates the fields of two descriptors by number, then routes a value into whichever field happens to carry the same number in the renumbered descriptor. Concretely, for a table whose proto is numbered first_name=1, <2 skipped>, last_name=3, id=4, copying between the two descriptors writes last_name (source 3) into id (target 3) and fails with:

IllegalArgumentException: Wrong object type used with protocol message reflection.
Field number: 3, field java type: LONG, value type: java.lang.String

This fix carries the index over whenever both sides agree on it, by the same rule already used for the field name. Indexes are kept only when all of them survive, since normalizeFields() renumbers every field as soon as a single one is missing an index.

This matters for today in AbstractArrayConstructorValue.resolveElementType() (the element type of a multi-row VALUES list).

Note the defect is latent on main. The issue is only surfaced in case of EXPLODE result wrapped in RCV. Currently, wrapping in RCV happens for WITH ORDINAL case, but not without out. As I make RCV wrapping default in #4623 , skipped-field-number-proto.yamsql fails owing to reason described above.